<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Class.php 16541 2009-07-07 06:59:03Z bkarwin $
 */

/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';


/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Class extends Zend_Cache_Core
{
	/**
	 * Available options
	 *
	 * ====> (mixed) cached_entity :
	 * - if set to a class name, we will cache an abstract class and will use only static calls
	 * - if set to an object, we will cache this object methods
	 *
	 * ====> (boolean) cache_by_default :
	 * - if true, method calls will be cached by default
	 *
	 * ====> (array) cached_methods :
	 * - an array of method names which will be cached (even if cache_by_default = false)
	 *
	 * ====> (array) non_cached_methods :
	 * - an array of method names which won't be cached (even if cache_by_default = true)
	 *
	 * @var array available options
	 */
	protected $_specificOptions = array(
        'cached_entity' => null,
        'cache_by_default' => true,
        'cached_methods' => array(),
        'non_cached_methods' => array()
	);

	/**
	 * Tags array
	 *
	 * @var array
	 */
	private $_tags = array();

	/**
	 * SpecificLifetime value
	 *
	 * false => no specific life time
	 *
	 * @var int
	 */
	private $_specificLifetime = false;

	/**
	 * The cached object or the name of the cached abstract class
	 *
	 * @var mixed
	 */
	private $_cachedEntity = null;

	/**
	 * The class name of the cached object or cached abstract class
	 *
	 * Used to differentiate between different classes with the same method calls.
	 *
	 * @var string
	 */
	private $_cachedEntityLabel = '';

	/**
	 * Priority (used by some particular backends)
	 *
	 * @var int
	 */
	private $_priority = 8;

	/**
	 * Constructor
	 *
	 * @param  array $options Associative array of options
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	public function __construct(array $options = array())
	{
		while (list($name, $value) = each($options)) {
			$this->setOption($name, $value);
		}
		if ($this->_specificOptions['cached_entity'] === null) {
			Zend_Cache::throwException('cached_entity must be set !');
		}
		$this->setCachedEntity($this->_specificOptions['cached_entity']);
		$this->setOption('automatic_serialization', true);
	}

	/**
	 * Set a specific life time
	 *
	 * @param  int $specificLifetime
	 * @return void
	 */
	public function setSpecificLifetime($specificLifetime = false)
	{
		$this->_specificLifetime = $specificLifetime;
	}

	/**
	 * Set the priority (used by some particular backends)
	 *
	 * @param int $priority integer between 0 (very low priority) and 10 (maximum priority)
	 */
	public function setPriority($priority)
	{
		$this->_priority = $priority;
	}

	/**
	 * Public frontend to set an option
	 *
	 * Just a wrapper to get a specific behaviour for cached_entity
	 *
	 * @param  string $name  Name of the option
	 * @param  mixed  $value Value of the option
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	public function setOption($name, $value)
	{
		if ($name == 'cached_entity') {
			$this->setCachedEntity($value);
		} else {
			parent::setOption($name, $value);
		}
	}

	/**
	 * Specific method to set the cachedEntity
	 *
	 * if set to a class name, we will cache an abstract class and will use only static calls
	 * if set to an object, we will cache this object methods
	 *
	 * @param mixed $cachedEntity
	 */
	public function setCachedEntity($cachedEntity)
	{
		if (!is_string($cachedEntity) && !is_object($cachedEntity)) {
			Zend_Cache::throwException('cached_entity must be an object or a class name');
		}
		$this->_cachedEntity = $cachedEntity;
		$this->_specificOptions['cached_entity'] = $cachedEntity;
		if (is_string($this->_cachedEntity)){
			$this->_cachedEntityLabel = $this->_cachedEntity;
		} else {
			$ro = new ReflectionObject($this->_cachedEntity);
			$this->_cachedEntityLabel = $ro->getName();
		}
	}

	/**
	 * Set the cache array
	 *
	 * @param  array $tags
	 * @return void
	 */
	public function setTagsArray($tags = array())
	{
		$this->_tags = $tags;
	}

	/**
	 * Main method : call the specified method or get the result from cache
	 *
	 * @param  string $name       Method name
	 * @param  array  $parameters Method parameters
	 * @return mixed Result
	 */
	public function __call($name, $parameters)
	{
		$cacheBool1 = $this->_specificOptions['cache_by_default'];
		$cacheBool2 = in_array($name, $this->_specificOptions['cached_methods']);
		$cacheBool3 = in_array($name, $this->_specificOptions['non_cached_methods']);
		$cache = (($cacheBool1 || $cacheBool2) && (!$cacheBool3));
		if (!$cache) {
			// We do not have not cache
			return call_user_func_array(array($this->_cachedEntity, $name), $parameters);
		}
		$id = $this->_makeId($name, $parameters);
		if ($this->test($id)) {
			// A cache is available
			$result = $this->load($id);
			$output = $result[0];
			$return = $result[1];
		} else {
			// A cache is not available
			ob_start();
			ob_implicit_flush(false);
			$return = call_user_func_array(array($this->_cachedEntity, $name), $parameters);
			$output = ob_get_contents();
			ob_end_clean();
			$data = array($output, $return);
			$this->save($data, $id, $this->_tags, $this->_specificLifetime, $this->_priority);
		}
		echo $output;
		return $return;
	}

	/**
	 * Make a cache id from the method name and parameters
	 *
	 * @param  string $name       Method name
	 * @param  array  $parameters Method parameters
	 * @return string Cache id
	 */
	private function _makeId($name, $parameters)
	{
		return md5($this->_cachedEntityLabel . '__' . $name . '__' . serialize($parameters));
	}

}
